<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div {
            width: 100px;
            height: 100px;
            border: 1px solid red;
        }
        /* .one:hover~div {
            background-color: red;
        } */
        /* .one:hover+div {
            background-color: red;
        } */
        /* .two:hover~div {
            background-color: red;
        } */
        .two:hover~div {
            background-color: red;
        }
    </style>
</head>
<body>
    <div class="one">1</div>
    <div class="two">2</div>
    <div class="three">3</div>
</body>
</html>